Telephone installation in wireless telegraphy



L. N. BHILLOUIN AND G. A. BEAUVAIS. TELEPHONE INSTALLATION IN WIRELESS TELEGRAPHY.

APPLICATiON FILED JUNEIB, I917- Patented Jan. 24., 1922.

2 SHEETS-SHEET I.

L. N. BRILLOUIN AND G. A. BEAUVAIS. TELEPHONE INSTALLATION IN WIRELESS TELEGRAPHY.

APPLICATION FILED JUNE 13, I917- 1,464,578, Patented Jan. 24, 1922.

2 SHEETS-SHEET 2.

UNITED 'SF'IFIATES PATENT OFFICE.

LEON NICOLAS BRILLOUIN, F PARIS, AND GEORGES ARMAND BEAUVAIS, OF LYON, FRANCE.

TELEPHONE INSTALLATION Application filed June 13,

To all whom, it may concern:

Be it known that we, LrioN NICOLAS BRILLOUIN and Gnonous ARMANI) BuAUvAis, both citizens of the French Republic, residing the first one at Paris, France, and the second one at Lyon, France, have invented certain new and useful Improvements in Telephone Installations in Wireless Teleg- 1'apl1y.'(for which I have filed applications in France, March 27 1916, and November 7, 1916; Belgium, February 2, 1917; Italy, February 6, 1917; Great Britain, February 22, 1917, and Russia, March 24, April 6, 1917,) of which the following is a specification.

' his invention relates to telephone instal- 1ations, particularly for wireless telcgraphy.

he invention has for its object to make it possible to arrange at the receiver stations a number of special electron tubes comprising a filament heated by an electric current, and two electrodes, the electron tubes being intended to act as an improved amplifier and the connection of the said electron tubes being moreover made more simply than hitherto.

The invention consists chiefly in using as an amplifier at the receiver stations of the installations of the kind in question, a certain number of special electron tubes comprising a filament heated by an electric current, and two different electrodes, and whilst connecting the second electrode of an electron tube to the first electrode of the next electron tube, and the first electrode of the first lamp to the line, the second electrode of each electron tube being moreover connected through a resistance to one of the poles of a source of current-in inserting a condenser into each of the connections of the electrodes with each other.

Apart from this main invention comprises more fully described in The invention will be following description ing drawings given by' arrangement, the other arrangements the following. understood from the and the accompanyway of example.

he Improvements are mainly intended Specification of Letters Patents IN WIRELESS TELEGRAIPHY.

'Patented J an. 24, 1922. 1917. Serial No. 174,633,

receiver tern-finals and then may be included in wireless telegraphy installations with a detector. It may be used in a further application thereof as an amplifier on telephone installations and the receiver ,terminals respectively connected to the two lines conducting the current from the transmitting station to the receiving station.

Fig. l is a diagrammatic view of receiver stations and telephone installation embodying the features of the invention.

Fig. 2 is a similar view showing a modified. structure.

Fig. 3.is a similar view showing a still further modified structure.

Figure 4 is a diagrammatic view illustratin an explanatory curveof working.

Figure 5 illustrates an installation similar to that shown in Figure 1 but showing another modification. v

A certain number .of special electron tubes a a a are taken, each comprising a filament (1 a a which can be heated by a source of electricity, a first electrode a a a next to the filament, having for instance the shape of a rid (electrode hereinafter referred to by t e name of grid) and a second electrode a a a separated from the filament by the grid and constituted for instance by a. cylinder or by a plate (this electrode being hereinafter referred to by the name of "plate.) v

The property is utilized which such electron tubes possess, that is to say, if to the grid is applied a variable tension 0) and to the plate a constant tension V, therewill pass from the hot filament to the two electrodes, electronic currents of respective intensities i and I which vary with the variable tension c.

A source of electricity 5 (storage or primary batteries) is taken, intended to supply current for heating the filaments (1 a a of the lamps a a, at, and the said filaments are connected to the terminals of thesaid source of electricity, made in parallel.

Another source of electricity 0 is taken, intended to produce the tension 2: in the plates a a, a- One of the terminals of the said source 0 is connected to the terminal of o posite polarity of the source of electricity 5, and the plates a, a, am are connected to the source of electricity 0, a resistance d,- d

other pole of the said being inserted between each of the said plates and the source 0. v U

One of the receiver terminals c of the installation is connected to that of the poles of the source b, which is connected to the source 0, and the other receiver terminal 6 to the grid a of the first electron tube, a condenser f beingp-referably inserted between the said termmal and the said grid. These receivers are of the kind hereinbefore explained. In the articular application of the improvements )llSt explained a wireless telegraphic installation without a detector is considered, and the improved device operates both as a detector and amplifier.

The plate a of the first electron tube is connected to the grid a'-"" of the second electron tube, a condenser f being inserted between the said plate and grid. Identical connections are made between the plates and grids of the next electron tubes.

Finally, the resistance that was to be inserted between the plate a of the last electron tube and the source of electricity 0, is

replaced by a telephone apparatus 9.

v In this way an installation is obtained in which, provided that the tension of the plates relatively to that of the corresponding filaments be such that electronic currents (which can pass only from the negative'to the posi-' tive) can pass from the said filaments to the said plates, an amplifying effect is produced from one electron tube to the next one.

In fact, in case of an increase of voltage of the grid a produced by an emission of current into the line (in the case of ordinary telephony) or by a reception of waves (in the case of wireless telegraphy) and transmitted to the grid a if necessary through the condenser 7, the intensity of the current passing in the plate a is also increased, and this in such a manner that the variation of voltage in the plate will be considerably greater than the variation of voltage in the grid. It may be noted that this variation of voltage in the plate is of opposite sign with respect to the variation of the voltage in the grid. In fact, the increase of voltage in the grid coming from an outside source which renders such grid more positive, will cause-a certain number'of electrons to be attracted to and retained by the plate, because. of its high positive potential. It is known that these particles'give a negative charge to a neutral plate and will consequently render the plate'less positive, i. e., dimimsh its positive potential. The electronic current which lessens the potential of the plate will then be neutralized by a current 80 flowing from the battery into the plate. This effect can be'foreseen by a simple consideration of Ohms law. On the one hand, as

soon as an electronic action. is established, a

current is established in the plate to neutralme the electronic current, but at this moment there exists a drop of potential due to the resistance d inserted between the battery and the plate a ()n the other hand, the electronic current increases with an increase of potential of the grid. The increase of voltage in the grid thus produces a decrease of the voltage in the plate. The resistance d should have a zero value in order that the potential in the plate may remain unaffected. This results in a corresponding variation of the voltage and of the current passlng through the grid a and in a still greater variation of the voltage and of the intensity of the current passing through the plate a and so on, these variations being now negative and now positive, and generally speaking, alternately negative and positive, because, owing to the existence of the resistances d, to each increase of current in one plate -will. correspond in the same plate a proportionahfall of potential.

In order that the transmission of variations of voltage of a plate to the next grid may take place While the mean voltage of the grid is maintained at a suitable value near that of the voltage of the filament, a condenser is inserted between the ,plate and the grid, owing to which the variations'of voltage are transmitted without the average voltage of the different grids being transmitted. With this end in view, each grid is connected by means of a resistance h k h to a potentiometer j connected across the terminals of a source of current is, one of the terminals of which is connected to the positive terminal of the source of. current I), owing to which the mean voltage of the grid can be fixed at a suitable value. It will be understood from the immediately foregoing conditions that the resistances d are not eliminated, but, on the contrary, are embodied in the organization as hereinbefore explained. In telephone installations, or in Wireless telegraphy installations, wherein it isunnecessary to rectify the current, the potentiometer will have to bepreterably'adjusted so that the grid has a mean-negative voltage relatively to the whole of the filament, in ordgr to avoid any current passing into the gri But as in wireless telegraphy it is indispensable to have a current rectifier, it is possible to combine the amplifier with the current rectifier, to render it possible to detect the mean current. In this case, the adjustment of the poten tiometer'must be such as to maintain the mean voltage of each grid at a positive value relatively to the whole of the corresponding filament, an absolutely essential condition for obtaining rectification of the current.

An examination of the curvc A A (Figure 7) indicating variations of intensity i of the electronic currents arriving at the grid, as a function of the potential vgof the grid, willin fact show that this curve has a very pronounced curvature in one portion corresponding to .a positive voltage greater than the voltage of the filament.

The curve D D shows the variation of the intensity I in the plate in accordance with the variation of the voltage not the grid, the voltage of the plate being supposed to re: main constant. Big. 4 also shows another curve C C which is obtained as follows: It is supposed that the grid has a mean voltage 0 but that the said voltage is subjected to sinusoidal variations with respect to the said mean voltage '0 and that the said varia'- tions have a constant frequency and a constant amplitude and the current i is the mean current of the grid. The curve C U will coincide with the curve A A when the latter assumes a straight line but will differ therefrom byreason of the curvature of the said first-mentioned crve. In fact then the variations of the potential (around the mean potential) will produce instantaneous variations of intensity in the current of the grid and the positive -variations will be stronger than the negative ones in consequence of the curvature. This results in an increase in the mean intensity and the curve C C passes over the curve A A If it is supposed that the grid is connected through aresistance It (having a value 1') to a point having a voltage 11 (point B of Fig. 4) the true voltage of the grid will be given: first, if there are not continuous waves, by the point a where the curve A A intersects with the line B B (line given by the equation o=o z' r) second, if continuous waves are sent in the grid by the point of intersection of the curve C C with'the line B B The presence of sustained waves produces a variation of the mean voltage of the grid and the said variation .roduces itselfa variation of the current Tof the plate, which latter variation is a continuous one and can be detected in the telephone.

The conditions of best sensitiveness require such an adjustment of the potential n at the point of connection of the resistance it to the potentiometer, that the. straight line B B intersects the curves'A A and C 0 at two points at a' distance from each other, and also such a construction of the electron tubes and such an adjustment of the potential V of the plate assured by the source of current 0, and of the heating of the filament, that the curve D D increases as quickly as possible with the potential of the grid.

In the case of wireless telegraphy, it is generally speaking advisable moreover to choose the capacities f f of as small values p as possible, in order that only the high frequency is transmitted from one electron tube to the next, the low frequency being stopped.

The amplifier-detector thus connected, constitutes a filterwhich greatly reduces the secondary currents and the injurious strong tron tube, amplified by ,the next electron tubes.

The installation could be very advantageously completed by certain auxiliary connections having for their object to increase the amplifying, the said auxiliary connections couldbe moreover applied e ually to any installations comprising ampli ers provided with the special electron tubes mentioned above, whatever he the method of connecting the said electron tubes.

For instance, as shown in Figure 2, it would be possible to use capacities Z 1 connecting the plate of one electron tube to the grid of one of the preceding lamps. Thus the same transmission is caused to pass twice through one electron tube, and the amplifying is modified. More particularly, a

capacity a (Figure 5) between the grid and tion and even to suppress the amplifying for a frequency exceeding a given limit shown by Fig. 5 at s, the remaining part of. this diagram being similar to the organization hereinbefore described.

In the case Where the reception takes place in a resonant circuit, and more particularly in the case of Wireless telegraphy, it may be advisable, whatever be the type of amplifier .with special electron tubes, amplifying the oscillations received, to connect that of the terminals 6 of the condenser of the oscillating circuit of reception, which is not connected to the installation and is merely connected to the grid a to the plate of one of the electron tubes, the voltage of which undergoes an increase when the voltage of the grid a increases (generally plate of an electron tube of even series) in the case of the amplifier (shown in Figure l), and this either by an adjustable capacity, or even by a resistance. The same result can be moreover obtained by the usual connections, owing to the unavoidable capacity exwith it, the said terminal 6 could be connected by another variable capacity or .resistance to the plate of an electron tube in which the voltage decreases when the voltage of the grid a l increases (generally plate of an electron tube of odd series).

These two connections can be preferably made or broken at will by means of variable capacities. Mechanical arrangements easy to design will make it possible-to control these two reactions by a single movement.

For example, as shown in Figure 3, it would be ossible to use a condenser q having two xed electrodes q, 9?, each connected by means of an adjustable resistance 1, T to a variable point of the resistance 03, of two different electron tubes or, and

also, a movable electrode 9 connected to the terminal-e and brought at willopposite one or the other of the fixed electrodes.

\ It is thus that continuous and gradual regulations can be arranged for, making it possible to bring the system very near to the state where the oscillations produced come into step or the regulation of the apparatus is 'such that it begins to heterodyne,

which state corresponds to a very strong amlplifying. n this way, by production of oscillations maintained in the reception circuit, it

is possible to receive directly, by interference without it being necessary to use an auxiliary heterodyne, waves emitted by any wireless telegraphy station with sustained waves and to receive with a very great amolification emissions from stations with damped oscillations'or waves.

Finally, if he regulation is effected near the limit of coming into step of oscillations in the circuit,- there will be received, in the absence of these oscillations and with their natural sound but very strongly amplified, the waves emitted by stations with damped waves. 1

It should be noted that, in order to obtain a regular working, it is advantageous to use the following'arrangements:

' Sucha construction of the resistances that their self-inductanceand capacity is entirely negligible, for which reason they are pre erably made from a very short high resistance wire, for instance by means of a very thin deposit of metal on an insulating support or on carbon.

It is useful to limit nection wires.

The source of current of the apparatus may advantageously be connected to any the length of the eonmetal arts comprising elements of the 'installation such, for example, as buttons, I

hin es, squares, bolts and t Obvious y the inventlon 1s not limited to the methods particularly indicated, but

com-prises on the contrary any modifications w1th1n the scope of the claims.

Having now particularly described and ascertained the nature of our said invention e metal springs of t e tele hone operator helmet.

and two different e ectrodes, one of which is connected through a resistance,'for the first electron tubes and through a receiving apparatus, for the last electron-tube, to a second source of current of given voltage, the other electrode being connected to a potentiometer through a resistance and being, also, connected by a condenser, for the first electron tube, to one of the terminals of. the receiving station and, for the other electron tube, to the plate of the preceding electron tube; the plate of one electron tube being connected by a capacity to the grid of one of the, preceding electron tubes.

2. A receiver station for installations of the classes specified, having'a number of electron tubes, each electron tube bein provided with a filament heated by an e ectric current furnished by a first source of curtube, the terminal of the. receiving station,

which is not' connected to the grid of the first electron tube, being connected; to that 'of the poles of the first source which is connected to the second.

3. A receiver station for installations of the classes specified, having 'a number of electron tubes, each electron tube being provided with a filament heated by an electric current furnished by a first source of current and two different electrodes, one of which is connected through a resistance to a second source of current of given voltage, the other electrode being connected to a potentiometer one of the terminals of which is connected to the'positive terminal of the first source of current through a resistance and being, also, connected by a condenser, for the first electron tube, to one of the terminals of the receiving station and, for the other electron tubes, to the plate of the preceding electron tube and the filamentsot' each electron tube bein connected in parallel to the terminals 0% the first source of current.

4. A receiver station for installations of the classes specified, having a number of electron'tubes, each electron tube being provided with a filament heated by an electric current furnished by a first source of current and two different electrodes, one of which is connected through a resistance, for the first electron tubes, and through a receivmg apparatus, for the last electron tube, to a second source of current of given voltage, the other electrode being connected to a potentiometer through a resistance and being also connected by a condenser, for the first electron tube, to one of the terminals of the receiving station and, for the other electron tubes, to the plate of the preceding electron tube.

In testimony whereof we have hereunto set our hands in presence of two subscribing witnesses.

LEON NICOLAS BRILLOUIN. I GEORGES ARMANI) BEAUVAIS.

- Witnesses:

CHAS. l. PRESSLY, PAUL BLUM. 

